AWS Certified Developer – Associate (DVA-C02) — Question 296

A photo sharing application uses Amazon S3 to store image files. All user images are manually audited for inappropriate content by a third-party company. The audits are completed 1-24 hours after user upload and the results are written to an Amazon DynamoDB table, which uses the S3 object key as a primary key. The database items can be queried by using a REST API created by the third-party company.

An application developer needs to implement an automated process to tag all S3 objects with the results of the content audit.

What should the developer do to meet these requirements in the MOST operationally efficient way?

Answer options

• A. Create an AWS Lambda function to run in response to the s3:ObjectCreated event type. Write the S3 key to an Amazon Simple Queue Service (Amazon SQS) queue with a visibility timeout of 24 hours. Create and configure a second Lambda function to read items from the queue. Retrieve the results for each item from the DynamoDB table. Tag each S3 object accordingly.
• B. Create an AWS Lambda function to run in response to the s3:ObjectCreated event type. Integrate the function into an AWS Step Functions standard workflow. Define an AWS Step Functions Wait state and set the value to 24 hours. Create and configure a second Lambda function to retrieve the audit results and tag the S3 objects accordingly after the Wait state is over.
• C. Create an AWS Lambda function to load all untagged S3 objects. Retrieve the results for each item from the REST API and tag each S3 object accordingly. Create and configure an Amazon EventBridge rule to run at regular intervals. Set the Lambda function as a target for the EventBridge rule.
• D. Launch an Amazon EC2 instance. Deploy a script to the EC2 instance to use the external database results to tag the S3 objects accordingly. Configure a crontab file to run the script at regular intervals.

Correct answer: B

Explanation

Option B is correct because AWS Step Functions standard workflows can natively pause execution using a Wait state for up to one year, allowing the manual 1-24 hour audit to complete before invoking the second Lambda function to apply the tags. Option A is incorrect because SQS visibility timeout has a maximum limit of 12 hours, making a 24-hour delay impossible. Options C and D are less operationally efficient as they require polling all untagged objects or managing infrastructure (EC2), which introduces unnecessary overhead and scaling issues.